Kidneys are vital organs of the humans homeostasis system. Kidneys act as a natural filter in the body which remove toxic metabolic wastes such as urea from the blood. Kidney failure or malfunction may lead to an accumulation of toxins and to an imbalanced electrolyte level in the blood, which may result in undesirable repercussions that are hazardous to an individual's health. In this regard, patients with impaired kidney functionality will usually have to undergo dialysis for the removal of toxic wastes in the blood and for the restoration of the optimal level of electrolytes in the blood.
For the past few years, the predominant form of dialysis used for patients with end-stage renal disease (ESRD) is hemodialysis. Hemodialysis involves the use of an extracorporeal system for the removal of toxins directly from the patient's blood by passing a large amount of the patient's blood through a filtering unit or dialyzer. In conventional hemodialysis processes, patients must spend hours immobilized throughout the duration of the dialysis, encumbering the patient's mobility. Another drawback of hemodialysis is the need to utilize an anticoagulant during the treatment process, which may inevitably increase the risk of internal hemorrhages.
The other form of dialysis used for patient with kidney failure is peritoneal dialysis, most commonly applied in the following two techniques: “continuous ambulatory peritoneal dialysis” (CAPD) and “automated peritoneal dialysis” (APD). In CAPD, fresh dialysate is infused into the patient's abdominal (peritoneal) cavity where, by means of diffusion, metabolic waste and electrolytes in the blood are exchanged with the dialysate across the peritoneal membrane. To allow sufficient diffusion of the electrolytes and metabolic waste to occur, the dialysate is retained in the abdominal (peritoneal) cavity for a couple of hours before removal and replacement (of the spent dialysate) with fresh dialysate. Major drawbacks of continuous ambulatory peritoneal dialysis are a low level of toxin clearance, and the need to continuously replace the spent dialysate, which can be arduous for the patient and disruptive to his/her daily activities.
To overcome the above-mentioned problems of conventional hemodialysis and continuous ambulatory peritoneal dialysis treatments, automated peritoneal dialysis (APD) devices have been developed in recent years. In APD, dialysis is performed at night, or while the patient is resting. The dialysate is exchanged and replaced automatically. This allows for more frequent changes of dialysate and better toxin clearance with minimal interruption to the patient's daily activities.
However, all dialysis techniques described above still suffer from several drawbacks. For example, hemodialysis fails to remove protein-bound toxins, while peritoneal dialysis entails a significant loss of beneficial proteins for the patient. Hemodialysis CAPD and APD fail to provide optimal clearance for uremic toxins, because of limitation of application time and/or volume of dialysate used (due to cost constraints). In cases where the hemodialysis device comprises a regenerating unit, such as a sorbent that regenerates spent dialysate, the overall size and weight of these dialysis devices are often too large to be portable and therefore do not improve a patients' mobility. Such devices are also cumbersome due to the bulky nature of the sorbent used to ensure adequate removal of the toxins, which is a requirement resulting from the intermittent use of the device. In addition, the flow system of known regenerating hemodialysis devices requires a plurality of pumps, which in turn undesirably increases the overall size, weight and power consumption of the device.
There is a need to provide a flow system for a dialysis device that overcomes or at least ameliorates one or more of the disadvantages described above. There is also a need to provide a flow system for the dialysis device, which ensures proper and efficient functioning of the dialysis device without compromising on the size, weight and power consumption of the device.